<?php

echo "<center>";
if (isset($_POST['submit'])):
?>

<?php

$year = $_POST['username'];


if ($year %4!=0){
      echo '<bt>';
    
    echo $year ."<br>".'khong phai nam nhuan';
}


else if ($year %400==0){
      echo '<bt>';
    echo $year."<br>".'nam nhuan';
    
}


else if ($year %100==0){
      echo '<bt>';
    echo $year ."<br>".'khong phai nam nhuan';}
  
    else { echo $year."<br>".'nam nhuan';
    
}

?>


<?php

else:
?>




<html>
    <body>
        
        <form action="tinhNamNhuanNhapfile.php" method="Post">
            <h4> chuong trinh tinh nam nhuan </h4>
            <input type="text" name="username">
            <input type="submit" name="submit" value="text">
            
            
        </form>
        
        <?php
    endif;
        ?>
    </body>
</html>